AR?

Just purchased a new S&W sport model. The peep sight on it is just too small for these old eyes. I need some kind of scope. What do recommend a red dot or cross hairs. I need some input from a few of you that have both. I won't be using it for hunting just to use for target and home defence.

You are really going to have to decide what your preference and eyesight dictate. There are any number of "tactical" scopes and optics for this gun; you need to narrow it down. The red dot sights are good for some peoples eyes, the holo sights are the same basic idea in a different package and then we get to the more normal optical riflescopes in all their different offerings.

What type of optic do you want is the basic question that you must answer; what can you see thru or be comfortable using?
The red dot scopes are easy for the eye to "pick up" and place on target; generally, they would lack the clarity for long range target shooting. I personally prefer a 2-7 power scope (as my eyes are in a league with yours) with normal plain crosshairs.
Go to the largest sporting goods store near you and look thru different types and see that you can see comfortably thru. Not much of an answer I am afraid, but with the ar rifles you can do so many things with optics you would need to narrow it down to what type fits your needs.

I am getting a little old, myself and my eyes are not what they used to be. I like using the iron sights on all guns but have found that I can no longer do that. I just ordered (yesterday) one of those EOTech holographic sights to put on one of my ARs. I have three of them, I have a BSA "tactical" Red Dot on one, and a tiny little ghost ring sight on another one. An "internet" friend in England sent me the ghost ring sight. The third AR will have the EOTech put on it.

a warning about the EOTech, if you're near sighted, your eyes will have a hard time with it. because of how its set up, your eye will focus on the reticle and not on your target. but if you're not near sighted, they're great.
here is what i have on my AR and the magnifier is crystal clear and even clarifies the reticle. i let a friend play with it while we were out coyote hunting and since then he has called me a cheater every time we go out hunting.....i personally say its not cheating if you winhttp://www.amazon.com/Eotech-MPO-II-Holographic-Magnifier/dp/B004MC5Q6U

I felt terrible about spending $550 on the one I got. I thought about how I could buy a pretty nice gun for that much or a couple of plastic .380's - I could/would never spend over a grand for an optic!!

I would recommend you go to your local sporting goods store and check out a few different sights. Everybody has different eyes and sights that work for some people might not work for others. Something you might look into is a sight that has different reticles to choose from.

Rig your eyes are going bad. I would suggest you look into a lower powered optic like a 1-4x scope. Doesn't have to break the bank you could even get a straight 2.5x as well. I'm on my iPad so I will look a little later when I get on my laptop.